marlin+arduino+driver=OK marlin+arduino+ramps+driver=FAIL ? is ramps dead

Hi,

Quite new to RAMPS, but not to arduino. I'm trying to get a small china 2020 CNC machine working

- I have an arduino mega + a ramps 1.4 and 3 a4988 drivers. I have tested each driver 1 by 1 with a simple arduino sketch, they all work fine
- I upload Marlin-1.0.2-2 and try with ramps + repetier-host-1.6.2 and motors make high pitch noise on X, Y nothing (no amps used), Z worked fine > 1/3 working, i must have some step setting problems (set DEFAULT_AXIS_STEPS_PER_UNIT to 2560)
- i connect 1 driver to arduino following the ramps PIN, send some Gcode to X axis and get it to work a F at 25, send same command in repetier and it works fine using the X controls
- put back the ramps board on arduino, put back driver : X axis is not working ?? Does this mean that the ramps board has problems ? since the driver connected directly to arduino works ?

Not sure if making a wrong conclusion here ?

Edited 1 time(s). Last edit at 01/22/2017 09:47AM by bobdoll.

You are applying 12v to the 12v 5amps plug of the ramps? (for some reason some people like putting 5v in here and nothing moves)

Also do you have the micro stepping jumpers installed (3 jumpers under each pololu module)

yes there is 12V connected, with an amp meter to monitor the power usage from the motors.
The 3jumpers are all there on each controller

Thats really really odd then...

take a photo of your board... maybe that will show something (drivers in backwards, in wrong place, out by one pin etc)

The ramps is just wires from the mega to the pololu modules in the form of a pcb (+ caps and jumpers) , you could check the step direction and enable pins are getting from the mega to the stepper driver in seconds...

Also is you ramps down hard on the mega? you should not be able to see the pins.

Edited 1 time(s). Last edit at 01/22/2017 08:45PM by Dust.

Here is a picture, but outside the drivers orientation, from what i can tell not much can be plugged in the wrong way.
I guess my next step is to trace each connections with a multimeter to see all the pins connect properly to arduino

"DEFAULT_AXIS_STEPS_PER_UNIT to 2560" this is actually really high for a reprap, I wonder if you have found a bug...

try 80, just as a test

Might be the 5A fuse is dead on the Ramps?
Do you see 12V on the Vmot pins on the drivers?

I guess the fuse is OK since Z axis works fine, i also see power consumption when received gcode order. Z nothing

Try to send some real slow moves like " G1 F50 X20" to see, if the steps/mm are the cause for nonmoving but power consuming steppers

You might have a batch of bad jumpers? Only the housing without the bridge??

whatever i movements i send to X axis doesn't work (M18 works fine, i cut the current). but Z works fine (using the same motor, i move the cables).
I guess the board has connection prob on X & Z.

I wonder, i know the jumpers are for the steps control, but how does that work when i use the driver directly on arduino (with 12V power on the motor pin), it work just fine and there are no jumpers ?

all off is 3 low, which is valid for full stepping, its is loud and chunky movement, but works for testing.

Most use 1/16 on all axis to reduce noise

i changed the ramps baord and it all works fine, the board was defective somehow